Elevator cages often have cage doors in the form of a double sliding door, the door elements of which are displaceably arranged in a so-termed door lintel or door crossbeam, usually by means of rollers on rails. This transom is often fixedly arranged at the elevator installation and accommodates a drive for opening and closing the cage door.
Safety specifications for operation of an elevator installation often require that in normal operation an actuation of the cage door is possible only in the case of a position of the elevator cage in which the cage door corresponds with a shaft door. Entrainer rollers are for this purpose usually arranged at the shaft doors or in a shaft-door door transom and so act on a mechanical unlocking means or on entrainer yokes at the elevator cage so that actuation of the cage door is released only in the corresponding region.
Similarly, for safety reasons opening of a shaft door is usually provided in normal operation only when an elevator cage correspondingly stands in front thereof. This is similarly carried out by way of the described entrainer yokes and entrainer rollers in that usually the cage door drive drives the cage door elements with the entrainer yokes fastened thereto, the entrainer yokes again drive or entrain the entrainer rollers at the shaft and these in turn open or close shaft door elements. In principle, the entrainer rollers at the shaft can be arranged directly on the shaft door elements or in a shaft door lintel.
However, due to one-sided loading of the elevator cage a skewed setting thereof can occur, which within the predetermined tolerances or within the play in the guides at the guide rails is accompanied by an alignment error of the elevator cage transom. This alignment error of the elevator cage transom in turn can mean that an asymmetrical release of the entrainer yokes, or even no actuation of the mechanical unlocking means and release switch possibly connected therewith, of the cage door opening takes place at the arrangement, which is usually in pairs or in quadruples, of shaft door entrainer rollers. The cage door and shaft door actuation thus does not function reliably or cage door blocking fault alarms are triggered.
The cause of these disturbances is often an alignment error, which possibly arises due to unbalanced loading of the elevator cage, of the elevator cage with respect to the shaft door or the absence of positional correspondence between elevator cage and shaft door.
The published specification JP-A-11011841 discloses a door lintel for a story door which is fastened to the shaft wall by means of slots and a hanging housing so that, in the case of fire shaft, door elements which expand due to the action of heat do not jump out of the guides. Because it can be technically difficult to realize in another manner, and because the shaft door elements are higher than wide, the disclosed arrangement is confined to vertically arranged slots. Apart from the fact that merely a door lintel of a shaft door and not a cage door is described, there is no compensating movement of the shaft-door door lintel in anything other than vertical direction. Thus, the proposal of a solution for the above-described problem of the absence of positional correspondence between the elevator cage and the shaft door is also not suggested.
A further published specification JP-A-05178570 discloses a mounting, which is pivotable within limits and thus positionally precise, of a shaft-door door lintel by means of several screws with an eccentric shank. However, once in the state of being mounted, no further compensating movement is provided.